Semiconductor device and method of manufacturing the same

Abstract

In a semiconductor device, a CoSi 2 film is interposed between a pluglike contact and a barrier metal film as a silicide film. Consequently, excess reaction can be suppressed on a Ti/polysilicon interface between the pluglike contact or a pluglike local wire and the barrier metal film for stably lowering contact resistance.

What is claimed is:  
     
       1. A semiconductor device comprising the discrete elements of: 
       a lower connected portion being a lower conductor portion;  
       a connecting portion electrically connected with said lower connected portion;  
       a layer essentially consisting of silicide having resistivity of not more than 100 μΩ.cm is provided to cover the upper surface of said connecting portion;  
       an interlayer isolation film covering the layer essentially consisting of silicide, the interlayer isolation film including a vertical hole connecting with the layer essentially consisting of silicide;  
       a barrier metal film over the layer essentially consisting of silicide and electrically connected with the connecting portion; and  
       an upper connected portion having a lower surface covered with the barrier metal film, the upper connected portion including a wire portion in said vertical hole and an upper conductor portion.  
     
     
       2. The semiconductor device according to  claim 1 , wherein said connecting portion includes a conductor embedded in a hole communicating with said upper connected portion and said lower connected portion. 
     
     
       3. The semiconductor device according to  claim 2 , wherein said upper connected portion includes a bit line contact. 
     
     
       4. The semiconductor device according to  claim 2 , wherein said upper connected portion includes a capacitor contact. 
     
     
       5. The semiconductor device according to  claim 2 , wherein the lower end of said connecting portion is directly connected to a source or drain region provided on a semiconductor substrate without through a silicide film. 
     
     
       6. The semiconductor device according to  claim 2 , wherein the lower end of said connecting portion is directly connected to a gate electrode. 
     
     
       7. The semiconductor device according to  claim 1 , wherein said connecting portion is a local wire formed by a conductor filling up a groove communicating with said upper connected portion and said lower connected portion. 
     
     
       8. The semiconductor device according to  claim 1 , wherein said silicide is any material selected from a group consisting of CoSi 2 , TiSi 2 , NiSi 2 , PdSi, ZrSi, HfSi, PtSi, CuSi, AuSi and AgSi. 
     
     
       9. A method of manufacturing a semiconductor device comprising: 
       a metal film forming step of forming a metal film on the upper surface of a connecting portion containing polysilicon electrically connected to a lower connected portion for electrically connecting said lower connected portion with an upper connected portion;  
       a silicification step of heat-treating said metal film and said connecting portion for causing silicification between said metal film and said connecting portion thereby forming a silicide film;  
       a metal film removing step of removing a part of said metal film not silicified in said silicification step;  
       an interlayer isolation film forming step of forming an interlayer isolation film to cover said silicide film;  
       a perforation step of providing a vertical hole in said interlayer isolation film, said vertical hole connecting with said silicide film; and  
       a wire foing step of forming a wire portion including a conductor in said vertical hole and on said interlayer isolation film.  
     
     
       10. The method of manufacturing a semiconductor device according to  claim 9 , wherein said silicide film consists of any material selected from a group consisting of CoSi 2 , TiSi 2 , NiSi 2 , PdSi, ZrSi, HfSi, PtSi, CuSi, AuSi and AgSi.